30/60/90 Day Sumation Query - sql

Question

I have the following query. It pulls invoice and time entries, and calculates the EHR (effective hourly rate) for each client, on a per month basis. What I need to get is:
company ,agreement ,lastMonthEHR,60dayEHR,90dayEHR,6MoEHR,12MoEHR,LifeEHR
CompanyA,AgreementB, 30.45, 27.76, 55.22, 30.75, 30.00, 25.00
EDIT:
I apologize for the format. I'll see if I can format it better. The following query returns monthly invoices, with EHR calculated.
SELECT a.AGR_Name, AGR_Type.AGR_Type_Desc, c.Company_Name, ap.InvoiceDate,ap.Revenue,ap.Hours,ap.EHR
FROM AGR_Header AS a INNER JOIN Company AS c ON a.Company_RecID = c.Company_RecID
LEFT JOIN AGR_Type ON a.AGR_Type_RecID = AGR_Type.AGR_Type_RecID
LEFT JOIN (
SELECT ar.AGR_Header_RecID,ar.Revenue,ac.InvoiceDate,ISNULL (ac.Hours, 0) AS Hours,
CASE
WHEN ac.Hours IS NULL THEN (ar.Revenue)
WHEN ac.Hours <= 1 THEN (ar.Revenue)
ELSE CAST (ar.Revenue / NULLIF (ac.Hours,0) as NUMERIC (9,2))
END AS 'EHR'
FROM (
SELECT ah.AGR_Header_RecID,
DATEADD(month,ai.Month_Nbr-1,dateadd(year,ai.Year_Nbr-2000,'2000-01-01')) as InvoiceDate,
CAST (ai.Monthly_Inv_Amt AS NUMERIC (9, 2)) AS Revenue
FROM
dbo.AGR_Header AS ah INNER JOIN
dbo.AGR_Invoice_Amt AS ai ON ah.AGR_Header_RecID = ai.AGR_Header_RecID
GROUP BY ah.AGR_Header_RecID, ai.Month_Nbr, ai.Year_Nbr) as ar
LEFT JOIN (
SELECT ah.AGR_Header_RecID,SUM(te.Hours_Actual) AS Hours, dateadd(month, datediff(month,0,te.Date_start),0) as InvoiceDate
FROM
dbo.Time_Entry AS te INNER JOIN
dbo.AGR_Header AS ah ON te.Agr_Header_RecID = ah.AGR_Header_RecID
WHERE (te.Agr_Header_RecID IS NOT NULL) AND (te.Agr_Hours IS NOT NULL)
GROUP BY ah.AGR_Header_RecID, dateadd(month, datediff(month,0,te.Date_Start),0)) AS ac ON ar.AGR_Header_RecID = ac.AGR_Header_RecID
AND ar.InvoiceDate = ac.InvoiceDate) AS ap ON ap.AGR_Header_RecID = a.AGR_Header_RecID
ORDER BY Company, Agreement, InvoiceDate

Answer 1

The SQL you posted is pretty complicated, but I think it can be simplified. I think the key is to get the invoice data into a format that is similar to the following:
DECLARE #invoice AS TABLE(
[ID] INT,
[CompanyID] INT,
[InvoiceDate] DATE,
[Hours] DECIMAL(9,2),
[Revenue] DECIMAL(9,2))
From there, the calculations are pretty simple, and they can be done using CASE WHEN statements with minimal subselects (I used one just for clarity, but even that one could be eliminated). Here's a full working example for SQL Server:
--Setup table and dummy data
DECLARE #invoice AS TABLE(
[ID] INT,
[CompanyID] INT,
[InvoiceDate] DATE,
[Hours] DECIMAL(9,2),
[Revenue] DECIMAL(9,2))
INSERT INTO #invoice VALUES(1, 1, '2013-01-01', 5, 100)
INSERT INTO #invoice VALUES(2, 1, '2013-02-01', 6, 100)
INSERT INTO #invoice VALUES(3, 1, '2013-03-01', 7, 100)
INSERT INTO #invoice VALUES(4, 1, '2013-04-01', 8, 100)
INSERT INTO #invoice VALUES(5, 1, '2013-05-01', 9, 100)
INSERT INTO #invoice VALUES(6, 1, '2013-06-01', 10, 100)
INSERT INTO #invoice VALUES(7, 1, '2013-07-01', 11, 100)
INSERT INTO #invoice VALUES(8, 1, '2013-08-01', 12, 100)
INSERT INTO #invoice VALUES(9, 2, '2013-04-01', 5, 100)
INSERT INTO #invoice VALUES(10, 2, '2013-05-01', 6, 100)
INSERT INTO #invoice VALUES(11, 2, '2013-06-01', 7, 100)
INSERT INTO #invoice VALUES(12, 2, '2013-07-01', 8, 100)
--Calculate last month start and end dates
--Hardcoded here for brevity
DECLARE #lastMonthStartDate AS DATETIME
DECLARE #lastMonthEndDate AS DATETIME
SET #lastMonthStartDate = '2013-08-01'
SET #lastMonthEndDate = '2013-09-01'
--Calculate EHRs for different time periods
SELECT
A.CompanyID,
CASE WHEN A.LastMonthHours = 0 THEN 0 ELSE A.LastMonthRevenue / A.LastMonthHours END as [LastMonthEHR],
CASE WHEN A.Last60DaysHours = 0 THEN 0 ELSE A.Last60DaysRevenue / A.Last60DaysHours END as [Last60DaysEHR],
CASE WHEN A.Last90DaysHours = 0 THEN 0 ELSE A.Last90DaysRevenue / A.Last90DaysHours END as [Last90DaysEHR]
FROM (
SELECT
[CompanyID],
SUM(CASE WHEN [InvoiceDate] >= #lastMonthStartDate AND [InvoiceDate] < #lastMonthEndDate THEN [Hours] ELSE 0 END) as [LastMonthHours],
SUM(CASE WHEN [InvoiceDate] >= #lastMonthStartDate AND [InvoiceDate] < #lastMonthEndDate THEN [Revenue] ELSE 0 END) as [LastMonthRevenue],
SUM(CASE WHEN [InvoiceDate] >= DATEADD(d, -60, GETDATE()) THEN [Hours] ELSE 0 END) as [Last60DaysHours],
SUM(CASE WHEN [InvoiceDate] >= DATEADD(d, -60, GETDATE()) THEN [Revenue] ELSE 0 END) as [Last60DaysRevenue],
SUM(CASE WHEN [InvoiceDate] >= DATEADD(d, -90, GETDATE()) THEN [Hours] ELSE 0 END) as [Last90DaysHours],
SUM(CASE WHEN [InvoiceDate] >= DATEADD(d, -90, GETDATE()) THEN [Revenue] ELSE 0 END) as [Last90DaysRevenue]
FROM #invoice
GROUP BY [CompanyID]
) A
I think this approach should work for you. I know I had to simply the problem to illustrate the way I would approach a query like this in my answer, so if you need me to expand on it please let me know.